Army Gen Martin Dempsey, chairman of the Joint Chiefs of Staff, told reporters here that the US wants more clarity on the militants in Syria.
"Clearly the picture we have of ISIS on the Iraqi side is a more refined picture," said Dempsey, using one of the acronyms for the Islamic State group. "The existence and activities of ISIS on the Syrian side, we have ... Some insights into that but we certainly want to have more insights into that as we craft a way forward."
Asked about the surveillance flights, Dempsey declined to comment, saying, "That was reported as a leak and I don't want to confirm or deny any of that."
Dempsey, who is in Kabul for the US military's change of command ceremony, has said he would recommend the military move against the Islamic State militants if there is a threat to the homeland.
Dempsey also said the US has been meeting with allies in the region to help develop a better understanding of the Islamic State group's threat. He said he believes those talks are now beginning to "set the conditions for some kind of coalition to form."
He said they are "trying to better understand the threat that ISIS poses, not just in Iraq and Syria but regionally." Dempsey has said he believes key allies in the region including Jordan, Turkey and Saudi Arabia will join the US in quashing the Islamic State group.
